FONTANA, Calif. -- Russian rookie Mikhail Aleshin's condition has been upgraded from serious to stable Saturday, according to IndyCar.

Aleshin suffered a concussion, broken right shoulder, broken ribs and other injuries to his chest in a two-car accident at Auto Club Speedway on Friday night during practice.

Aleshin was airlifted to Loma Linda Medical Center.

In a statement, IndyCar medical consultant Terry Trammell said overnight Friday: "Verizon IndyCar Series driver Mikhail Aleshin was evaluated at Loma Linda University Medical Center in Loma Linda, Calif., on Aug. 29 and diagnosed with fractured ribs, a broken right clavicle, a concussion and chest injuries. He was admitted to the hospital and listed in serious but stable condition."

Trammell confirmed Aleshin was conscious before being airlifted. He originally was complaining of right shoulder and right foot pain after the crash during a scheduled 30-minute final practice for Saturday night's IndyCar finale.

Trammell said Charlie Kimball, the other driver involved in the crash, was checked and released at the infield care center and cleared to drive Saturday.

Sam Schmidt, co-owner of Schmidt Peterson Motorsports, wrote in an email to USA TODAY Sports on Saturday afternoon:

"Went to the hospital this morning and Dr. Trammel's comments are spot on. He is recovering well and is being observed."

IndyCar safety workers were shown tending to Aleshin while he remained in the driver's tub of the No. 7 car for Schmidt Peterson Motorsports for several minutes after a vicious crash that occurred after 10 p.m. ET Friday.

Aleshin had dropped left-side wheels below the white line exiting Turn 3, causing a spin to the outside wall. Kimball was driving in the high lane, and the impact was fierce.

Aleshin's car was struck hard in the side and pitched into the fence, ripping it apart. A wheel assembly got caught in the Turn 4 fence. There are no fan stands in that area of the track.

Several cars trailing the accident had to take evasive action as debris scattered, including Marco Andretti's.

Kimball and Andretti exited their cars under their own power.

"It was a T-bone," Kimball said of the initial impact that sent Aleshin's car tumbling over twice.

Kimball said he didn't think Aleshin's tires would hold him to the bottom of the track, but when the spin started he thought he'd clear the trouble.

"Next thing I knew he was accelerating up the hill in front of me," he said. "It looked huge."

Ryan Hunter-Reay said the impact of Aleshin's car with the fence was a ''cheese grater situation. It's scary."

The 27-year-old rookie driver has started 17 IndyCar races this season, with one top-five finish (second in the second of two races in Houston) and seven top 10 finishes. He also has crashed out of five races, including Toronto where his car got stuck under that of Juan Pablo Montoya.

He's currently in 15th place in the standings.

Thoughts and prayers with @mikhailaleshin right now. That was a terrible accident. Gotta try and clear our heads and do the job tomorrow.

According to Indycar, Aleshin had just scored a timed lap of 33.4413 seconds (215.303 mph).

Drivers had asked IndyCar officials to move the final practice back so they could run under the lights and avoid the glare of the setting California sun, and the sanctioning body had agreed.

Conditions for Saturday night's MAVTV 500 finale will be similar to Friday's, with temperatures in the low 80s at race time, near sunset (10:20 p.m. ET, NBC Sports Network), then cooling off into the mid-70s.

Aleshin qualified eighth earlier Friday, a season-high for him on an oval.

The first Russian to race in the IndyCar series, the Moscow native has won on some of the best tracks in Europe, including Monza in Italy.

(Photo: Robert Laberge, Getty Images)

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"I've been racing in Europe now under the Russian flag for already 15 years; well, 14 years and now I'm racing in the U.S.," Aleshin, the 2010 champion in the World Series by Renault, told the Milwaukee Journal-Sentinel earlier this month. "We had some difficulties in start of '90s for some obvious reasons" — the breakup of the former Soviet Union — "but now it's getting bigger.

"I think a good indication of how IndyCar is interesting and important for Russia is that now from this year, IndyCar is shown on the main sports channel in Russia, live every race. So believe me, it's getting bigger and bigger every race and I'm getting really good feedback from some people who've never seen it before."

In 1999, Greg Moore was killed here in a crash on the 10th lap of what was then the CART series finale.

Less than a year ago, on Oct. 6, 2013, four-time IndyCar champion Dario Franchitti suffered career-ending injuries at a crash on a temporary street circuit in Houston when his car sailed airborne into a temporary catchfence in a three-car incident coming out of the super-quick Turn 5.

Franchitti broke his back and ankle and suffered a concussion. He retired from the sport a month later.